As if we needed one more way to truly appreciate the scale of Hurricane Harvey, new NASA satellite imagery offers a sobering dose of perspective: the storm's lingering trail of carnage is visible even from space.

Just 11 days before, the bodies of water were nearly invisible from space. As rain dumped by Harvey continues to drain toward the Gulf, however, the three larger rivers and several of their smaller tributaries have become mammoth features in the region's landscape.

More evidence of Harvey's presence lies where the rivers meet the Gulf. Large, brown plumes of sediment carried across the region by the raging floodwaters can be seen dissipating into the Gulf. Galveston Bay is nearly entirely brown from sediment in the satellite imagery.

Environmentalists have raised concerns that the high volume of water moving across the state could be carrying toxic chemicals from the area's highly polluted Superfund sites into the Gulf. The Environmental Protection Agency said in a statement Saturday that it is working with local agencies to assess the condition of the Superfund sites and take appropriate action.